Quarter	Percent
1999-04-01	64.4
2000-04-01	61.4
2001-04-01	64.5
2002-04-01	62.3
2003-01-01	59.9
2003-04-01	59.9
2003-07-01	59.9
2003-10-01	59.9
2004-01-01	61.2
2004-04-01	61.2
2004-07-01	61.2
2004-10-01	61.2
2005-01-01	60.6
2005-04-01	60.6
2005-07-01	60.6
2005-10-01	60.6
2006-01-01	61.1
2006-04-01	61.1
2006-07-01	61.1
2006-10-01	61.1
2007-01-01	66.3
2007-04-01	60.3
2007-07-01	61.4
2007-10-01	66.6
2008-01-01	67.1
2008-04-01	55.5
2008-07-01	56.7
2008-10-01	62.2
2009-01-01	51.3
2009-04-01	45.9
2009-07-01	54.5
2009-10-01	57.5
2010-01-01	52.1
2010-04-01	48.4
2010-07-01	52.2
2010-10-01	52.1
2011-01-01	50.9
2011-04-01	54.8
2011-07-01	49
2011-10-01	51.6
2012-01-01	49.5
2012-04-01	55.1
2012-07-01	52.4
2012-10-01	49.7
2013-01-01	47.2
2013-04-01	48.7
2013-07-01	50.8
2013-10-01	51.5
2014-01-01	52.1
2014-04-01	45.3
2014-07-01	48.6
2014-10-01	45.7
2015-01-01	50.6
2015-04-01	51.2
2015-07-01	59.2
2015-10-01	57.2
2016-01-01	50.5
2016-04-01	49.3
2016-07-01	52.8
2016-10-01	51.0
2017-01-01	49.7
2017-04-01	52.0
2017-07-01	55.3
2017-10-01	55.5
2018-01-01	53.7
2018-04-01	54.2